It will be weeks before the cause of the blaze, which came within 300m of homes in Ravensbourne on Tuesday, is known, but a joint investigation by the Fire Service and the Otago Rural Fire Authority is under way.
At the height of the operation, 40 firefighters from eight fire appliances and six helicopters battled the blaze. Adding to the firefighting costs will be the clean-up.
Firefighters and contractors will remain at the site in coming days to ensure the fire does not reignite.
Yesterday, 19 firefighters and contractors worked at the fire ground ''mopping up'' from about 7am, Mr Still said.
Yesterday morning, he flew over the pine forest and scrub which the blaze tore through, identifying ''smokies'' and hot spots which needed the attention of firefighters.
The fire would not be considered out until rain fell over the West Harbour area.
''We need rain,'' he said.
''It's never out until we get substantial rain.
''We do our best, but we only have to miss something the size of your thumbnail [for wind to reignite it].''
A specialist fire investigator from the Fire Service and Mr Still were investigating the cause of the blaze.
The fire started near the bottom of Signal Hill in the scrub behind Logan Park High School, he said.
It was too early to determine if it was suspicious.
''Put it this way - it wasn't a lightning strike,'' Mr Still said.
''We don't know how it started. It could have been accidental.
''We will go through the process and eliminate a certain cause and then come to a conclusion.
''We should have an idea within a couple of weeks.''
Despite the extent of the blaze, no property had been damaged nor anyone injured.
As firefighters first arrived at the top of Signal Hill, their first concern was whether any mountain bikers were on the tracks which ran through the area. Luckily no-one was there.
''Thank God,'' Mr Still said.
''They would have been toast had they been halfway down the hill.''
Firefighters, with the assistance of monsoon buckets, were able to stop the fire as it reached native forest about 200m-300m from properties at the top of Rimu St, Ravensbourne.
''They did a hell of a good job in trying conditions,'' Mr Still said of firefighters on the ground and of the helicopter pilots, working in smoke and high winds.
''In the real scheme of things what have we burnt? We have burnt some radiata and some gorse. No properties have been threatened or damaged and no lives, so it's pretty good in the scheme of things. That's how I look at it.''
Firefighters had got lucky as wet weather throughout spring resulted in vegetation being much greener than at the corresponding time last year.
But there was no room for complacency.
''Just be careful. People think it's green, but with a bit of wind it doesn't take much.''
